Elevator hoist



2 Sheets-Sheet l M. B. M LAUTHLI N ET AL ELEVATOR HOIST T W [1 I LLLLLOriszilz ajl Filed Sept. 50, 1922 Nov, 29, 125i.

Nov. 29, 1927. Y 1,650,936

M. B. MCLAUTHLIN ET AL V ELEVA'J'JOR HOIST Original Filed Sept. 30, 19222 Sheets-Sheet 2 lqvenifim (7072a MDOJd 772,3. 7720;107:5715:

all)

Patented lhlov. 29, W2?

his,

IAZARTIN 3B. MCLAUTHLIN, OF MALDEN, AND JOHN W. 130101), QUINCY,MASSACHU- E-ZIEClTfi, ASSIGNORS T0 GEORGE T. MoLA'UTHLIll UUMPAEY, 01BOSTON, MASSrhCHU- SETTi-l, A GGRPORATION 0F RHODE I$LAND.

ELEVATOR HOIST.

Application filedfieptember 30, 1922, Serial No. 591,531. Renewed April27, 1927.

This invention relates to elevator hoists having been more particularlydesigned for dumb waiter service and where electric drive is employed.

C ne objectof this invention is to provide a construction by which thevalue ofthe current for the motor is reduced.

star ting to a minimum and wherein a comparatively small motor issutlioient to move the elevator car with a rapid and easy positive andneg ative acceleration and a high maximum speed. I

The reduction of starting current is a very important factor of economywhich becomes particularly apparent where a number of hoists areactuated from the same circuit, since it materially reduces the maximumloads thereon and renders the load in a given period more nearlyuniform. By reducing the starting current heavy overloads on the motorare eliminated and the motor overload protective devices may be set witha smaller margin so as to render them mor effective in safeguarding themotor.

One factor which aids in the accomplishment of this object consists incausing the weight of the motor armature to act as a counterbalance fortheelevator car.

Another factor resides in the constructio of the winding drum. y

A further feature of the invention resides in the winding mechanismwhereby one of the limits ofmotion of the elevator car is preciselydeterminedregardless of the exact position in which the motor comes torest- Other features and advantageous details and combinations of partswill appear from a more complete description of a preferred embodimentthereof disclosed in the accompanying drawings in which a Figure 1 is atop plan of themachine.

Figure 2 is a section online 2-2 of Figure 1 with parts broken away.

Figures 3 and i are end and side elevations; respectively, of thewinding drum and related parts. t

Figure is a top plan of the brake.

Figure 6 is a side elevation partly in seci "may be splashed thereondownwardly'mto tion along the lines 66 of Figurefi of the upper portionof the motor and the brake.

Figure 7 s an end elevation of the brake.

horizontal position.

Referring to Figures 1 and 2, 1 indicates a casing transversely ofwhichis journaled a winding shaft 2. This shaft extends outwardly at one sideof the casing and. carries the windingmechanism indicated generally at 3and which will later be described more. in detail. Within the casing theshaft 2 has fixed thereon worm wheel 4t. Extending inwardly from thelower portion of the casing opposite this worm wheel is a bearing lug 5in which is journaled the lower end of a vertically extending shaft 6which carries thereon a worm 7 meshing with the worm wheel 4. As shownthe casing is formed in two parts, the lower part 8 extending up wardiyand containing the lower halves of the bearings for the shaft 2 and theupper part 9 having therein the upper halves of these hearings and madefast to the lower section by means of bolts 10 passing through matingflanges 11 and 12 on the upper and lower sections, respectively. Thecasing thus furnishes a compartment in which the worm wheel and wormextend which may contain lubricant, and as shown, an upwardly ext-endingpipe 13 communicates with the interior of the section 8 and furnishesmeans by which lubricant may be supplied thereto.

Supportedon the upper section 9 is a motor casing 15, the shaft 6 beingthe armature shaft for the motor, the armature being indicated at 16.This motor casing may be of any usual type suchras is normally designedto operate with the armature in a l/Vith a motor of this type thefcet 17on which it is normally supported in the horizontal position furnishsuitable'supports to which a panel board 18 for the motor controllingdevicesmay be attached. One end cap of the motor may be replaced by acap 20 which may rest and be made fast on an outwardlydirected flange 21of the upper casing section 9. This cap is provided with a bearingopening 22 through which the shaft 6 passes audits lower face ispreferably formed frusto coni cal in order to direct any lubricant whichthe casing. To further prevent the escape of lubricant from thiscasingabout the shaft, a deflecting shield, indicated at 28, may be fixed tothe shaft 6 immediately below the member 20. The armature shaft 6extends upwardly and may be supported from the end cap 25 of the motorby ball bearings indicated at 26. Above the ball bearings 26 the shaftextends through a brake mechanism indicated generally at 30. With thisconstruction the weight of the armature and shaft imparts a downwardthrust on the worm wheel which serves to counterbalance to some extentthe pull exerted by the winding cable on the drum 3.

This drum 3 is indicated in detail in Fig ures 3 and 4 and comprises acentral circular portion 35 having a winding groove thereon for thecable, the portion 35 at opposite ends leading into portions ofprogressively smaller diameter toward the ends of the drum as indicatedat 36 and 37, these porions having cable grooves therein formingcontinuations of the cable groove or path of the portion 35. The outerend of this drum terminates in a shoulder 35 which prevents the cable aswound on the drum from sliding endwise therefrom. The inner end of thedrum has a one-direction clutch face 39 thereon. This face as showncomprises an inclined portion 40 terminating in a substantially axiallyarranged driving face 41. Cooperating with this clutch face is a matingclutch element 42. The drum is keyed to the shaft 2 while the clutchelement 42 is slidable and rotatable thereon. The inner face of thisclutch element has a shoulder i3 to prevent the slipping of the cabletherefrom and the element is normally urged into clutching engagementwith the drum by means of a coil spring 4% surrounding the shaft 94reacting between it and a portion of the casing 1.

The winding direction of the shaft 2 is such as to bring the drivingface 41 of the clutch face against the clutch element 42 so as to imparta positive rotation thereto. In the unwinding direction, however, thedriving is exerted through the inclined face 39 so that shouldresistance to the rotation of the clutch element 42 occur it may stopits rotation, being merely forced axially away from the drum against thepressure of the spring .4 by the action of the inclined face 39. Thecable 46 to which the elevator car (not shown) is attached is wound onthe drum and is made fast at the opposite end as by means of an eye bolt47, to the clutch element .13. In this construction as the drum isturned to wind up the cable, the clutch element is positively driven asabove described and the cable is wound'starting on the clutch element.which has a small wind ing diameter, and from thence passing to thecomparatively small diameter inner end portion of the winding drum. Thissmall diameter causes the winding to be started at a comparatively slowrate and consequently relieves the starting load on the motor to a verylarge extent. This is particularly desirable where alternating currentmotors are employed which are essentially constant speed motors and arenot readily and economically controlled by speed-governing devices. Thestarting load on the motor is therefore reduced so that the rush ofstarting current is rendered small and the motor is not overloaded. Assoon as the car is under way, however, the cable begins to Wind on theincreasing diameter of the drum so that its rate of speed is rapidlyincreased until it reaches the maximum where the cable is being wound onthe large diameter central portion 35. It is then desirable to slow downthe speed of the car in order that it may be brought to rest withoutshock, and for this purpose the final winding is effected on a graduallydecreasing diameter portion of the drum until the cable is completelywound and the car has reached the desired limit. of travel. At thispoint the current is cut olf from the motor which is immediately stoppedby the brake mechanism which will presently be described. \Vhen the drumis rotated in the reverse direction to pay out the cable the same actionon the ele ator car takes place. That is, it starts with a low velocity,is given a rapid positive :wceleratiom and then is given a rapidnegative acceleration until it llnally tops and this with asubstantially constant motor speed. It is possible to so proportion theparts that the motor would be unable to start the car if the windingwere started on the large diameter of the drum, but by start ing on thesmall diameter it is amply able to accelerate the car to the speedproduced by winding on the large diameter. A comparatively small motor,therefore, is thus fully capable of doing the work required. The clutchelement 42, to which the end of the cable is attached, is used to insurea uniform limit of motion of the car on the unwinding of the cable.\Vhen the cable is all unwound, as shown in Figure l. further rotationof the drum 3 in the unwinding direction, would tend to wind the cablein the reverse direction. As in this direction of rotation the clutchelement is not positively driven, any tendency to rewind the cable cffects a resistance to the rotation of the clutch element which in thisdirection is sufficient to stop its movement even though the drum 3should rotate thereafter. the clutch element moving axially of thedriving shaft 2 but not being rotated. This effects a constant limit ofmotion of the elevator car in one direction even though the winding drumshould not stop its rotation precisely at the same point. as it mayoverrun without effecting the winding of the cable. When the drum isdriveii in the winding direction, however, a positive clutchingengagement is effected with the element 42 so that the cable starts towind positively as the clutch element is not permitted to unclutchtherefrom in this direction of rotation.

The braking mechanism above referred to is shown in detail in Figures 5to 7. The armature shaft 6 shown in Figure 6 e1-ztends above the motorcasing cap 25 and has lined thereto a disk 50. As shown this disk isprovided with a hub 51 through which passes a tapered pin 52 which alsopasses through a mating hole transversely of the shaft 6 and keys thetwo for simultaneous rotation. Between the lower face of the disk andtheupper face of the cap 25 is positioned a ring shaped support 58 throughthe central opening of which the shaft 6 loosely passes and it issufi'iciently thin so that it may have a slight vertical motion betweenthe lower face of the disk 50 and the upper face of the cap 25. Thissupport is prevented from rotating relative to the cap 25 by anysuitable means. As shown this means comprises pins 5% seated inperforations in the upper face of the cap 25 and extending into mating'ierforations in the support 53. Above the plate 50 is positioned a ringmember 60 having at spaced points vertically perforated lugs 62. Throughthe perforations in these lugs are passed rods 63 which are threaded attheir lower end in portions 6-4 extending outwardly from the support 53beyond the periphery of the disk 50. These rods 63 have thumb screws '65threaded on their upper ends and bearing be tween the lower faces ofthese thumb screws and the upper face of the disk 60 are compressionsprings 66. These springs are so positioned as to urge the ring 60toward the support 53 so as to bring their opposed faces againstopposite faces of the disk 50. These opposed faces are preferablyprovided with frictional. material of any suitable description asindicated at 70. When these springs are allowed to act, therefore, thering 60 is forced against the upper face of the disk 50 while thesupport 53' is raised upwardly from the top face of the cap 25 andengages the lower-face of the disk. This normal position of the parts isthen the position in which the armature shaft is braked againstrotation. For the purpose of releasing this mechanism to permit freerotation of the shaft 6 electromagnetic devices are indicated. Eachdevice comprises an electromagnet -72 carried by the support 58 andhaving passing through the central axis of its core T20 a non-magneticpush rod 73. This rod engages the under face of the lug 62 between sideflanges 74 depending there from on opposite sides of the core 720, andwhich prevent relative rotation of the ring 60 and the motor casing,since the support 53 is prevented from such relative rotation &

by means of the pins 55. The lower end of e ch core 73 rests loosely onan armature 75 loosely carried by screws 730 from the magnetframe 731and which when the magnet is energized, is drawn upwardly against thelower face of the magnet. The length of the rod 73 is so proportioned,however, that when the arn'iature 75 is brought up wardly the lug 62 ispushed upwardly by the rod to force the ring 60 away from the sup port.This motion is sulhcient in extent to permit the support 53 to drop downon to the upper face of the cap 25, thus entirely freeing it fromengagement with the disk 50 and also to force the ring 60 upwardly to anextent sutlicient to disengage it from the upper face of this disk. isdeenergized the armature falls away there from and rests on the uppersurface of a leaf spring 732 bridging the bolts 730, this spring holdingthe armature, rod and lug in contact to prevent rattle. The magnets 72are connccted in the control circuit of the motor so that whenever themotor is energized these magnets are also energized, thus releasing thebrake. As soon as the motor-actuating cu r rent broken these magnetsfail to be energized and the springs 66 apply the brake as abovedescribed.

The machine as above described in which the motor is arranged verticallyalso provides a compact construction requiring little floor space andincluding the panel board of substantially constant horizontaldimensions throughout its height. It is thus capable of being employedin places where room is restricted. Furthermore the vertical position ofthe armature shaft'facilitates ventilation of the motor, since air canpass to the armature through openings near the lower end of the motorcasing and escape through the usual openings provided in the upper endcap. 7 c

It will be seen from the above description that a winding mechanism hasbeen provided which permits an easy and rapid motion of the elevator carwith a comparatively small expenditure of energy, and while a preferredembodiment has been disclosed in the draw-r ing, it should be evident tothose skilled in the art that many modifies ions and changes might bemade therein without departing from its spirit or scope as defined bythe appended claims.

VVe claim! 1. Amachine of the class described comprising a winding drum,a cable to be wound on said drum, and a motor for actuating said drumhaving a rotating element, said rotating element being so disposedrelative to said drum that its weight acts thereon in opposition to thepull on the cable.

2, A machine of the class described com prising a winding drum, cable tobe wound on said drum, and a motor for driv- W hen the magnet So i ingsaid drum, said motor having a part acting by its weight on said drum ina direc tion opposed to the pull of the cable thereon.

3. A machine of the class described C0111- prising a winding drum, acable to be Wound on said drum, a Worm wheel fixed to rotate with saiddrain, a vertically positioned Worn: meshing with said worm Wheel, and amotor rotor fixed to said worm to impart by its weight an axial thruston said worm acting in opposition to the pull of the cable on said drum.

4. A machine of the class described, coniprisinq a winding druni, acable to be Wound on said drum, a worm wheel iixed to rotate with saiddrum, a casing for said worin Wheel, a motor supported by said casing,said motor having a vertically arranged armature, a Worm fixed to rotatewith said armature and meshing with said worni Wheel, the weight of saidarmature and Worm acting on said drum in opposition to the pull exertedthereon h said cable.

5. A machine of the class described comprising a casing, a shaftjoin-aided horizontally in said easing a worm wheel lined to said shaftWithin said casing, a motor lixed to the top of said casing and havingits rotor arranged vertically, a rotor shaft extending downwardly intosaid casinq a worm lixed to said shaft and meshing with said worm wheel,said casing being constructed to receive a lubricant in which said wormand worm wheel extend and a lubricant deflector carried by said shaftabout said \xOllll acting to prevent the passage of lubricant out fromsaid casing about said shaft.

(1. 1n a device of the class described, a shaft a winding drum lixed tosaid shaft, said drain having a central Winding portion of comparativelylarge diameter and end portions 01 pr gressively decreasing windin;diameter; in directions away from said central portion, an elementhaving a small winding diameter slid-able and rotatable on said shaft,said drum and element having uniting one-direction clutch faces, meansnorn'ialiy urging said element into clutching rehition to .llltl drum,and a cable to he wound on said element and drum having one end lined tosaid element.

in testimony whereof we have allixed our signatures.

JOHIN' \V. DODD. lvliili'lIN B. MCLAUTHLIN.

